/*
  将下面异步代码使用 Promise 的方法改进
  尽量用看上去像同步代码的方式
  setTimeout(function () {
    var a = 'hello'
    setTimeout(function () {
      var b = 'lagou'
      setTimeout(function () {
        var c = 'I ♥ U'
        console.log(a + b +c)
      }, 10)
    }, 10)
  }, 10)
*/

function delay(time) {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      resolve();
    }, time);
  });
}

async function fn() {
  await delay(10);
  var a = "hello";
  await delay(10);
  var b = "lagou";
  await delay(10);
  var c = "I ♥ U";
  console.log(a + b + c);
}

fn();
